The electronic configuration of the elements A and B are 1s², 2s ²,2p⁶,3s² and 1s², 2s²,2p⁵ respectively. The formula of the ionic compound that can be formed between these elements is ___________

(a)

AB

(b)

AB₂

(c)

A₂B

(d)

none of the above

In which of the following options the order of arrangement does not agree with the variation of property indicated against it?

(a)

I< Br < CI < F (increasing electron gain enthalpy)

(b)

Li < Na < K < Rb (increasing metallic radius)

(c)

Al³⁺< Mg²⁺ < Na⁺ - (increasing ionic size)

(d)

B < C < O < N (increasing first ionisation enthalpy)

Various successive ionisation enthalpies (in kJ mol^-1) of an element are given below.

IE1	IE2	IE3	IE4	IE5
577.5	1,810	2,750	11,580	14,820

The element is

(a)

phosphorus

(b)

Sodium

(c)

Aluminium

(d)

Silicon

Identify the wrong statement.

(a)

Amongst the isoelectronic species, smaller the positive charge on cation, smaller is the ionic radius

(b)

Amongst isoelectric species greater the negative charge on the anion, larger is the ionic radius

(c)

Atomic radius of the elements increases as one moves down the first group of the periodic table

(d)

Atomic radius of the elements decreases as one moves across from left to right in the 2^nd period of the periodic table.

The correct order of electron gain enthalpy with negative sign of F, Cl, Br and I having atomic number 9, 17, 35 and 53 respectively is _____________

(a)

I > Br > Cl > F

(b)

F > Cl > Br > I

(c)

Cl > F > Br > I

(d)

Br > I > Cl > F